How to Choose An E-Bike Conversion Kit: Everything You Need to Know
Want to convert your regular bike to an e-bike? Here’s what you need to know.
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You love riding your bike but are frustrated by other riders who fly passed you as you struggle up the slightest incline. Or maybe you’re just tired of showing up to work in a sweaty shirt.
Or maybe you’re a DIY’er and already have a perfectly functioning bike and want to upgrade to something with a little (or a lot) more pep. In either case, you want to join the e-bike revolution.
You’re in luck. E-bike conversion kits make it easy to keep your current bike while reaping the rewards of electric motors with minimal cost.
Motor Types and Strength
There are several ways to build a DIY e-bike, and they all depend on the kind of motor you choose in your conversion kit: mid-drive, direct-drive hub, or friction-drive. A mid-drive motor is integrated into the lower-middle section of the bike frame, generally in between the pedals. A direct-drive hub motor is integrated into the front or rear wheel hub. A friction motor is mounted with a roller that contacts your rear wheel.
Each motor type has pros and cons. Hub motors are less expensive and easier to install, but they offer less torque, and the added weight on the front or rear wheel can affect the bike’s balance. Mid-drive motors are more expensive and difficult to install but offer more torque and put the added weight in the center of the bike, making it more balanced. Friction motors are the easiest to install but offer minimal performance gains.
There are various e-bike classes, and e-bike conversion kits are no different. When comparing the power of different kits, you’ll be comparing the watts of each motor. Wattage (or the number of watts) refers to how much power a motor requires to run. Motors with more watts will deliver more torque. Most e-bike conversion kits fall between 250 and 1,000 watts, but some jurisdictions restrict e-bike motors, so check your local laws before buying.
How much power does your e-bike need? That depends. E-bike conversion kits with hub motors are usually better suited for flat roads and long distances. In contrast, mid-drive conversion kits are usually better suited for people carrying more weight or living in hilly areas. The amount of power your motor requires will also affect the range.
Ease of Installation
At first glance, e-bike conversion kits might seem daunting to install yourself, but these small, powerful kits can be very easy to connect.
Friction-drive kits are the easiest to install. For example, the Rubbee conversion kit attaches to your bike’s seat tube using a few bolts and rests on your bike’s rear wheel.
Direct-drive hub motor kits are the second easiest to install. All you need to do is replace your front or rear wheel with a new one that includes an integrated motor. It might take some ingenuity to find a place to mount your battery and electronics, especially in a way that keeps your bike looking clean, but anyone with a few basic tools and some zip ties can install this kind of kit.
Mid-drive motor kits are the most difficult to install but are still easy for people who are handy and can work on their bikes. The installation will generally require you to remove and reinstall your bike’s cranks, chain, and chainring and attach the motor and sensors.
Battery Capacity
When comparing the battery of different conversion kits, you’ll be comparing something called watt-hours (referred to as Wh). Watt-hours refers to the number of hours a battery can produce one watt of electricity. E-bike batteries can be anywhere between 500 and 700Wh.
E-bike kits will vary in the distance they can let you travel. The size and capacity of the onboard battery, combined with the power of the motor, determine the distance you can ride. While bigger batteries are usually better, several factors can influence the longevity of your battery between charges, including the weight you’re carrying and the speed you’re traveling. Under typical demands, one mile will cost about 20 watt-hours.
Bike ev conversion kit
They rate the set up at 60 Ah- 87 V max- 76 nominal. Integrated BMS.
Custom headlight- taillights- turns- stripped everything down and repainted. fabricated the motor mount- headlight bracket- indicator lights- shaved the subframe and recovered the seat. after market lower fairing- mirror.
Its actually given me a lot of time to work on the bike itself. Been a lot of fun tweaking the design- trying to get it just the way I want it. If ID had the money for the conversion right away- I would have just built it without all the custom work.

I view building this bike as functional art. My inspiration comes from a mix of modern street-fighters- cafe-racers- and old school bobbers (emphasized by the flat-black with red wheels and brushed aluminum). And a little pimpin gold around the edges.
CellLog monitors on all cells.
And now some first ride at 84 volts:
THANKS TO ALL WHO POSTED THEIR PROJECTS HERE TO HELP ME DESIGN AND BUILD MINE.
Dec 10: Parked for the winter- with the charger on a timer so it gets a little juice each night.
Nov 24: Running reliably. I can ride it to work whenever the morning temp is over 38 degrees Fahrenheit and the pavement dry. Side panels are in place so the bike looks pretty nice- finally.
Nov 12: Hard freeze last night and it wasnt kind to the batteries. I barely made it to work. I may have to bring the bike indoors at night.- my garage is unheated.
Nov 6: The bike is running just fine. A short across the throttle switch kept the controller from booting- and it took a few days to diagnose. Controller now boots instantly. Clocks have changed and Im coming home in the dark- but Ill commute as long as the streets are dry. Meanwhile- as long as I had the wiring apart- I cut a hole in the bottom of the tank to provide clearance for the controller and a place to hide some of the cables. Looks a lot cleaner now.
Sept 30: Rewired to get all the bits under cover. Its a tight fit. Acquired a gold-plated fuse holder for the 250-amp ANN fuse and found room for it on top of the battery stack.
Sept 23: Want an original dolphin fairing to hide the mechanicals- and I also need to weatherproof (that is- hide) the snake nest of wiring.
Sept 20: Commencing daily commute- amongst the migrating SUVs. Feel like a gazelle amongst elephants. Controller sometimes takes awhile to boot.- something is sporadic in there.
Motorcycle Dragster. Massive DD Torque
Electric Motorcycle Burnout
DRZ SM electrique (84 volts)
DRZ SM electrique (12 volt test)
TTXGP Electric Motorcycle
Step 1
I only work 3 miles from home but with gas getting out of control, I thought it would be great to have an electric motorcycle. I’ve always wanted an electric motorcycle and decided that doing an electric motorcycle conversion with an electric motorcycle motor would be a good EV project, keeping costs down, and be fun to ride.
This project took about 3 months of research and development (not counting waiting for parts to come in or help from a friend with the welding). All in all, it cost about 3000 to build an electric motorcycle with a high performance electric motorcycle motor. This may take a long time to pay off in gas savings, but if you add the fun of building and all of the environmental benefits, it was well worth the effort. With a top electric motorcycle motor speed of over 70 mph and 10 miles per charge, this electric motorcycle is perfect for me. The following instructable will not give you exact step by step instructions, but if you have some mechanical skills and welding ability you should be okay. A little knowledge of electric motorcycle motor maintenance wouldn’t hurt, too. However, I just read the user’s manual and learned as I went.
Step 2
Every motorbike is different but the basic components can be the same. Below is a list of the parts I used and where I got them, but you will have to do some research to figure out what fits your bike and requirements. Check out the electric motorcycle photos at the bottom to see what I bought and the EVAlbum for other electric motorcycle conversions.
Frame : I looked at many different bike styles and decided on a 1984 Honda Interceptor for my electric motorcycle conversion for a few reasons:
1) I like the style of bike, not a total crotch rocket but not a hog either, with room for electric motorcycle batteries inside the frame. 2) The seller on Ebay was close to my house. And the bike didn’t run, so it only cost 600 which is a perfect price for your first time electric motorcycle conversion. If you have an old bike or someone will donate one then that’s greatbut for the rest of us, try the local paper, junk yards, Craig’s List or ebay motors.
Electric Motorcycle Motor :
After reading other electric motorcycle conversion specs (and knowing that I wanted to go faster than a moped), I chose a 72V electric motorcycle motor (DD Motorsystems carries many options), because it’s weight and dimensions where good for my frame.
Electric Motorcycle Batteries : I went with 6 Yellow Top Optima batteries from remybattery.com because they are sealed and have received great reviews. After making cardboard mock ups of the D23 model I realized that there was no way six full sized batteries would fit and still look good. I ended up getting the D51 model. Half the size and weight but also half the storage.
Electric Motorcycle Controller : You have to match your electric motorcycle controller to your voltage but the amperage is up to your budget. amps = more power and more cost. It seems that there are only two real choices: Alltrax or Curtis. You’ll have to decide for yourself, but I went with the 72V 450Amp Alltrax.(DD Motor Systems carries these) Don’t waste your time trying to build a potimeter on an old throttlejust buy a pre-made one and be done with it. I got the Magura 0-5K Twist grip throttle.
Electric Motorcycle Charger : You have to match your charger with your voltage but the speed of charge in Amps is also up to your budget. I went with a Zivan NG1 but I have recently switched to six individual 3amp Soneil chargers to help balance the batteries.
Electric Motorcycle DC/DC Converter : It’s safest to run with a DC/DC converter and an extra 12V battery backup but motorcycles have limited space so I am only using the converter. I purchased a Sevcon 72V Input 13.5V output from evparts and it has working perfectly.
Electric Motorcycle Fuses : You’ll want to get a fuse that matches your setup. I bought model ANN 400 w/ holder.(DD Motor Systems carries these)
Electric Motorcycle Solenoid : This is a device that you hook up to your existing key ignition on 12Volts and it will close the loop so you get the full power to your controller. An excellent Solenoid is the Albright SW-180B-12.(DD Motor Systems carries these)
Electric Motorcycle Battery cable and connectors. I bought about 10 feet of 2 GA wire from WAL-MART and cut it to length. Using Lugs, I soldered and used heat shrink tubing on each end. I highly recommend battery terminal covers for safety.
Electric Motorcycle Instruments I chose an E-meter(Link 10) w/ Prescaler add on for 72V use instead of a bunch of different meters. As an added feature I wired up the ignition switch to the neutral indicator to show me when the bike was on.
Electric Motorcycle Other parts Wire. 12GA different colors and heat shrink tubing (large and small sizes) Electrical tape Wire connectors Wire wrap
Tools Basic shop tools are required such as a socket set, screw drivers,wire stripper, etc. Additionally a volt meter, metal grinder and crimper are used in this electric motorcycle conversion project.
Step 3
Start the electric motorcycle conversion by removing all of those nasty internal combustion engine parts. Remove the gas tank and using your grinder or other cutting tool to cut out the bottom. This makes room for extra batteries or components. ( Make sure all gas is out before cutting ) Reference your owners manual often during any electric motorcycle conversions so that you don’t cut any necessary wires, and try to sell some of the parts to help pay for this electric motorcycle conversion project.
Next, make cardboard mock ups of all of your batteries and electronic components to see how and where things are going to fit. Take a look at my electric motorcycle conversions pictures to see how I fit everything, believe me that taking the time to make accurate cardboard mock ups is well worth the effort.
Now for the hard part. You need a secure battery box and electric motorcycle motor mount for any electric motorcycle conversion. I had a friend weld it up for me and he did a fantastic job. From the photos you can see that he first strung up the electric motorcycle motor to allow for minor adjustment to be made before cutting the electric motorcycle motor mount plate. After that was cut he made a nice chain and sprocket enclosure with a door and welded them onto the frame.
Next he fabricated the battery rack and gave each battery a swing arm closure to give a tight fit yet still allow me to get them out easily. Half inch foam padding spacers are between each battery to help cushion the stackbut believe me, they aren’t going anywhere. The last thing he did was weld in metal plates for mounting my electric motorcycle motor.
After you get your electric motorcycle motor mount and battery compartment all welded up, take some time to clean up the frame of your bike. I removed any rust spots and chipped paint that I could find. Then I used some metallic gray and black spray paint. This makes a world of difference and costs very little.
I made a fake gas cap and ran the power cord from the charger up the frame and out the top.
Now that you have all of the welding done and your electric motorcycle frame looks great, let’s install the electrical components and start wiring it up your electric motorcycle conversion.
Step 4
Wiring. This depends on the electric motorcycle components you buy. See the manufacturers wiring diagrams.
Step 5
Double check all of your connections and tighten every bolt.
I wanted my electric motorcycle conversions bike to look as good as it rides, so I had all of the panels painted and custom graphics made up by worldsendimages.
Using a serial cable and laptop, tweak the electric motorcycle controller program for your riding preferences.
Lastly, I got the electric motorcycle conversion bike inspected and insured. (Be prepared for the dealership mechanics to swarm and hit you with a bunch of questions and jokes about failing the emissions test).
I know these weren’t step by step building instructions, but that’s because of the complexity of this electric motorcycle conversion project and variables in component use. My intention was to give you the motivation to build your own by seeing how I did it and make it easier by supplying the electric motorcycle parts list and a wiring diagram. MSD
Think about the names given to electric cars and electric motorcycles on the market today.
Most, if not all, are a play on the concept of all-electric, zero tailpipe emissions travel.
So when we heard about a team of engineers in Henderson, Nevada who were developing a new electric motorcycle called Brutus 2, we had to investigate.
Retro Styled, Classic Charm
Squint at the all-electric Brutus 2 and you’d be forgiven for thinking it was a classic Harley Davidson bobber or perhaps an Orange County Chopper. ( build electric motorcycle )
Either that, or a working prop from a film set in a post-appocolyptic future, Mel Gibson optional.
Designed from the ground up to be the living embodiment of a sports cruiser, Brutus 2 is the first electric motorcycle we’ve seen that caters directly to fans of classic American motorcycles.
Brutus 2 is also the first real stealth electric motorcycle motor we’ve seen. Unless you look at it closely, it doesn’t immediately appear electric.
In fact, park it up beside similar gas motorcycles, and we think you’d have a tough time telling it apart from the rest.
It Isn’t Just Tough By Name
But as many classic motorcycle fans will tell you, good looks and a tough name will only get a motorcycle so far.
In order to be considered a real motorcycle, it has to perform like one.
That’s no problem for Brutus 2, claims Chris Bell, the original designer and owner of Brutus Electric Motorcycles.
Although it hasn’t had any official range, or performance tests, Bell claims the 535-pound motorcycle can spring from 0-60 mph in around 4.7 seconds, reach a top speed of over 100 mph, and travel over 100 miles per charge.
These impressive performance figures are apparently down to a five-speed clutchless transmission, a powerful DD Motor Systems DC motor, and a liquid-cooled Zilla controller more commonly found in electric drag race cars like BlackCurrent III
There aren’t any details published on battery pack capacity, although Bell claims Brutus 2 should recharge its 144-volt lithium-ion battery pack in 3 hours from an available 110-volt wall outlet. Using some basic math, we think that translates to a battery capacity of between 4 and 5 kilowatt-hours. ( build electric motorcycle )
Forbidden Fruit?
Here’s the catch: while Brutus 2 is certainly an real electric motorcycle motor built for real motorcyclists, it hasn’t entered production yet.
According to Bell, that should happen some time this year, provided current deals being discussed with various parts and manufacturing companies are signed.
But right now, the all-electric beast is nothing more than an impressive prototype motorcycle awaiting production.
And that’s a real shame, because we think this is exactly the kind of electric motorcycle that needs to be built in order to help convince mainstream motorcyclists that electric powered motorcycles can be mean and green at the same time. ( build electric motorcycle ) MSD
Making the case for an electric car. higher up-front costs, but then much less expensive and environmentally damaging to operate. to someone switching from a gasoline-powered car is pretty straightforward.
But convincing someone to trade in their Harley for an electric motorcycle? That could be more challenging. There has to be an element of cool. And speed.
Which is what two Purdue University students and AllCell Technologies set out to produce – and appear to have delivered, with an electric motorcycle that packs 72 kilowatts of power and, according to early tests, can hit 120 mph and cover 120 miles on a charge, according to AllCell.
The company said the trick to creating this high-performance bike was in the 10.6 kilowatt-hour lithium battery that uses AllCell’s thermal management material.
The phase change material graphite composite (PCM-graphite) controls the impact if one cell has an internal short circuit, and the PCM material absorbs and distributes heat away from the battery, protecting the cells and maximizing battery life.
While some motorcyclists might enjoy being daredevils, with this motorcycle riders can let ‘er rip and concentrate on driving without worrying about unnecessary things like an overheating battery. Apart from the battery, electric vehicle experts Tesla Motors and Delphi Corporation also provided support for the project, AllCell said.
This team is not alone in the quest for the superior electric motorcycle motor. There seems to be quite a trend in motorcycle conversion to electric in garages, notably from a fellow Purdue student who we reported used solar power to power his, yes that’s right, Solar Cycle.
However, for those of us who aren’t that confident in our mechanical skills, there are a growing number of companies producing electric motorcycles with both coolness (largely because of their green-factor) and impressive power and speed. ( electric motorcycle conversion )
The International Motorcycle Show starts in New York today, so the Jacob Javits Center will be awash in chrome-crusted cruisers weighing more than 600 pounds and packing car-size engines, and screaming superbikes with enough horsepower to fly a four-passenger airplane.
But some of the most intriguing machines at the show are small, light and nearly silent.
Electric motorcycles powered by lithium batteries are beginning to look like contenders in a bike market that is increasingly concerned about fuel efficiency, emissions and noise.
Electrics may attract customers who like the idea of two-wheel transport but are put off by the mechanical complexity of traditional motorcycles and the perceived difficulty in riding them. They may also have particular appeal to urban riders and commuters who can operate more easily within the bikes’ limited range.
I test-rode an electric sport motorcycle called the Zero S this and week and was surprised by how appealing it is even for someone who loves the chugging rhythm of a Ducati twin or the wail of an old Honda V4. The quiet whir of the electric motor and its impressive off-the-line acceleration made the Zero ideal for city riding, where hearing nearby traffic can be as important as seeing it.
While the motor puts out about 28 horsepower, it feels like much more, especially when accelerating from a standstill. I was able to leave menacing taxis far behind and the bike’s weight of less than 300 pounds gave it a light, athletic feel that made getting through midtown New York’s congestion enjoyable.
The Zero S has evolved since 2009, when I rode an early version. The new bike is faster, smoother and better-looking than its predecessor and has a tighter, well-finished feel. It’s ready for prime time.
As with electric cars, though, high could keep some customers away. The S and its on-road-off-road stable mate the DS start at 11,495. The higher-capacity battery that boosts range to 114 miles from about 76 miles with the standard battery also increases the price to 13,995. That amount would buy a Honda CBR1000RR, which is close to being a street-legal racing bike.
Of course riders interested in electric motorcycles are not cross-shopping superbikes. But the Zero’s price premium could hurt sales.
Still, the simple joy of riding the Zero could be as big a selling point as its potential fuel savings. In many ways its design and the way it rides are throwbacks to the minimalism and excitement of earlier motorcycles that drew so many people into riding decades ago.
While I tell people that my next new car will probably be electric, a battery-powered motorcycle, in some ways, would be a better fit.
Oakland California USA, Electric Motorsport Inc. has unveiled its two entries for the June/12th Isle of Man TTXGP. In the open class is a modified production electric motorcycle called the GPR-S. The Electric Motorsport GPR-S were the first Production Electricmotorcycles capable of attaining legal freeway speeds in the USA.
In the Pro Class, the entry is the Electric Motorsport R144. This conversion is based on an R1 race chassis. This motorcycle utilizes a high performance electric motor designed and manufactured by DD Motor Systems, Inc.
Electric Motorsport is a technology company that specializes in Light Electric Vehicles and electric propulsion systems. Electric Motorsport is proud to say they have supplied electric drive systems and components to many of the TTXGP teams that will be competing. Why does Electric Motorsport supply its competitors with hi-performance electric drive components? Electric motorsport Founder and CEO Todd Kollin says its mainly to promote the technology and to have some one to race with, and besides we are in the parts business. Racing is just the fun part and its not much fun without competition.
So Honda is getting into the electric motorcycle biz huh? Well, now we know what they plan to do with all the engineering talent suddenly available from their now defunct F1 AMA efforts.
Motorcycle News (via our friends at AutoBlogGreen) says Honda is serious about building a workable Ebike and selling it to the likes of you and me by 2010. Sure, that sounds plausible. Honda has the engineering grunt and it pretty much has the whole motorcycle thing down, so it seems like a lead pipe cinch.
Not exactly. Honda faces the same hurdles everyone else does: range and recharge times.
I spent some time with an outfit made electric scooters and motorcycles. It was a real geeky operation making scooters and souped-up jobs custom-built to customers’ needs, desires and checkbooks. Once or twice a year someone with sacks of money would come in and say something along the lines of Take my GSX-R and make it electric. We would, but we’d invariably face the same challenges everyone else building EVs faces: range and recharge times.
Yeah, we could build an electric GSX-R that would out haul Valentino Rossi. for about seven to 10 miles. Then you’d stop. And then you’d have to plug it in for six or eight or 10 hours. The bike was cool, but not very practical. You couldn’t take the thing up some canyon road on your way out of town to Palm Springs for a three day weekend. These will be the same limitations that Honda will face, but in a couple of not so noticeable ways, electric motorcycles play to Honda’s strengths.
For one, bikes are easy. They’re small, light and easy to work on. You can fab up and try things on two or three test mules in an afternoon, and that’s an order of magnitude or so harder with cars. For another, Honda is a bike company. Yeah, I know, tell that to Ayrton Senna and Alain Prost and Ron Dennis, but it started out primarily as a bike company (OK, go back far enough and it started out as a piston ring company, but still. ) then morphed into a car company. What Honda learns from making an Ebike over the next two years can, hopefully, migrate to cars.
Honda confirms working with bikes is favorable on a number of levels.
History shows that motorcycles remain strong in a difficult market environment and have always supported Honda in difficult times, says CEO Takeo Fukui. People showed renewed interest in the value of motorcycles which consume less fuel for commuting purposes as well as for their easy-to-own/easy-to-use efficiency.
Good point, Takeo. That’s another thing bikes got going for them: They’re cheap.
Pound for pound and dollar for dollar motorcycles are the best bet for enthusiast fun. Not for me, of course, because I am comically and frighteningly uncoordinated and that’s never a good thing on a motorcycle. But you get my point.
Think of what Honda is doing as a real world proof of concept scheme. Make an electric motorcycle. Make it work. Make it work better. Then import the technology into a car. Repeat the process.

Discovery Series E-Bike Conversion Kit
The Discovery Series is our longest range series. With a range of up to 100 miles, you are sure to have enough power. Give your old bike the boost it needs and revolutionize your biking experience.
Additional information
20 Wheel, 24 Wheel, 26 Wheel, 27.5/650B Wheel, 29 Wheel, 700c Wheel
Add Phone Holder (9.99), No Thanks!
Product Specifications
Model – ZM-D
Battery Capacity – 36V14.5Ah
Cell Quantity – 50 cells
Charging time – 7.0 hours
Battery Type – 18650 power lithium ion batter
Charger – AC110V – AC110V-AC220V, DC42V 2A
Assist Range – 50-100 miles
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The assist range is under conditions: 140 lb rider, outside temperature 78F, minimal wind, 50% assist level under manual mode, riding on flat level road.
Top Speed – 25 mph
Wheel size – 12″/14″/16″/20″/24″/26″/27.5″/28″/29″/700c
Rated Power – 350-500w
Motor Structure – Gear drive
Motor Efficiency – 80%
Max Torque – 40N.m
Wireless Connection – Bluetooth 5.0 (Allows the controller to connect to multiple devices at the same time)
Product Dimensions
Net weight (including rimtire) – 18 lbs
Package – 24 lbs
reviews for Discovery Series E-Bike Conversion Kit
I had some heart surgery about 2 years ago and was struggling to get some fitness back. This conversion kit has transformed my bike and my life. I think I sold 3 of your items this morning on the bike paths near my house. Love, love, love it thanks for making my life easier John
Go the distance. I actually started out with the smallest battery pack unit and it was great, but then i realized how much I loved riding. I upgraded to this and gave the other to my son. You cant get me off this thing now. We live on the beach and I cruise the boardwalk any chance I get.
Well the waiting for the kit did awhile from purchase… But I knew lead time from the start. When delivered it was easy to install and fit to my bike. So far I’ve had it a week and enjoying the benefit it gives when riding up hills. Gives me really good assistance. Just see how long it takes for battery to go flat and what distance or range I get out of it before recharge.
I purchased 2 kits I’ve installed one so far and it was fairly simplistic to do so. I just have to install one on my wifes bike. Cant wait to use more and get used to the assist. Great product!
i can’t comment on the quality of the ebike kit, because my bike was stollen before i got to use this. Regardless, customer service and response times were fantastic. Their money back guarantee proves their faith in the product, and it was really that…easy return and money back. Well done team and good luck in the future. I’ll be back
This is a great ebike kit only took about 20-30 minutes to set up on bike. I have a rad ebike, but after about 6 months of use its given me too much issues and now I have a large paper weight. I’ve been using this everyday on my bike and its heped me improve my life. For the price it cant be beat and I know I can get parts if needed or have my bike back if I want to take the kit off
Easy to fit, and excellent support…when the settings are at zero there’s no friction and rides freely. I was worried about the difference in peddling without the assist and there is none. I haven’t tried any major hills yet, but will be soon as I’m heading to Colorado.
Fab! I now enjoy going out on my bike whenever I can. I like to pretend I ride all the time and this battery may be overkill for me, but the security of knowing I have the extra juice was worth it!
Hi all. Further to my earlier review I thought I’d give an update. I’ve had this kit on my bike for almost six months. I find the battery holds it’s charge very very well. My bike is a 10 year hybrid and it is a joy to ride and was my main reason going with a kit. My rides are between 50 – 70 miles long. I prefer to use my thumb throttle on hills etc as well as peddling. Great for cardiovascular workout.
I use this on my trike and I actually pull a trailer for deliveries. I’m sure I get less mileage doing so, but still have no complaints. I go a full 8 hour shift before I have to charge.
Brought a kit for my wife’s bike and I was so impressed that I ordered one for myself. So far I am very pleased with both kits.
Seem all good up to now, website answered all the questions I had before I made my purchase. I then went on to buy the kit, it arrived within the time stated and fitting was relatively easy and am overall very pleased with it.
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Skarper’s revolutionary ebike conversion kit uses a disc-brake rotor to drive your bike
British start-up Skarper has unveiled a new e-bike conversion kit that uses a specially designed disc brake rotor to provide power to your bike.
Most electric bike conversion kits are not easily removable because of the effort involved in switching out a wheel, cables, batteries and fittings. However, the new Skarper system eliminates that issue by containing everything within a compact single unit that has a unique and patent-protected design to drive your bike’s rear wheel.
We’ve spent an afternoon using the system for an exclusive first-ride review and, so far, we’re impressed.
What you need to know about Skarper
- The Skarper unit requires you to replace the rear disc rotor with its rotor/drive unit
- It weighs in at a claimed 3kg
- Skarper’s rotor works as both brake and drive, and adds just 300g to your bike
- Once the disc is installed, fitting/removing takes seconds
- Claimed range of up to 60km
- Charge time of 2.5 hours
What is it?
Skarper’s electric bike conversion kit is housed inside a one-piece drive and battery unit. The unit clips onto specially designed tabs that you fit to your non-driveside chainstay.
The motor then drives a purpose-built rotor, which the brand has dubbed the DiskDrive. Most electric bike conversion kits use a front-hub motor, a bolt-on mid-drive unit or rear-wheel motor to provide propulsion.
Like most ebike conversion kits, on Skarper’s system, a cadence sensor attaches to the cranks to control power output.
Who is behind the Skarper ebike conversion kit?
Skarper says it has a team of more than a dozen engineers and designers working out of its London base. Leading development is inventor Dr Alastair Darwood.
Dr Darwood already has plenty of innovations under his belt associated with his medical training. These include orthopaedic and anaesthetic medical devices developed while working in the NHS.
Supporting Darwood’s innovative electric bike conversion kit is a group of cyclists who’ve all backed the company privately.
The Skarper’s investors include six-time Olympic and 11-time world Champion Sir Chris Hoy, who has also been heavily involved in the testing and development of the unit.
He explains: “I’ve always been an advocate of getting more people on bikes, regardless of their fitness, ability or age, and I’ve discovered that ebikes can play a huge role in making cycling more accessible to anyone.
“It opens up opportunities – whether it’s making a commute possible which would otherwise have been too difficult, keeping pace with a fitter friend for a challenging bike ride, returning to riding after an injury or illness, or just going further on your rides and seeing more for the same effort.”
The self-contained motor, battery and ‘brain’ of the system is remarkably compact and weighs in at just 3kg. Skarper
What’s next?
Skarper is remaining tight-lipped on the full details, but alongside the road/urban unit seen here, the brand has also been working with Red Bull Advanced Technologies on an off-road version.
Skarper claims this unit has “huge amounts of power and plenty of torque. It means you can clip-on the system to carry you to the top of the mountain, unhook it and stow it in your pack and then you’re free to ride the trails on your / without the added weight and expense of an e-mountain bike“.
When will it be available?
Skarper has now committed to full production, with delivery intended for 2023.
No fixed price has been set as yet, but Skarper tells us that the target price is £1,000.
Skarper also claims it’s in discussions with major bike brands about the opportunity to fit the DiskDrive disc brake rotor as standard.
Skarper electric bike conversion kit first-ride impressions
Warren Rossiter, senior technical editor
While at Skarper’s office, I fitted a prototype system to a modest Merida hybrid. This involved a switch of the centre-lock disc rotor for Skarper’s DiskDrive, attaching the Bluetooth cadence sensor to the cranks and then hooking the unit onto the rear chainstay, with its driveshaft plugging into the keyed slot on the rotor.
Taking the unit out of the box and getting it powered up and ready to ride took a matter of minutes.
I headed out onto the streets of Camden, in London, to try out the system.
The system provides assistance quickly from a standing start, progressively increasing the power smoothly and making for quick getaways from traffic lights.
We headed to Highgate hill, which rises around 60m in elevation. I came away impressed by how easily the Skarper coped with this short urban climb.
Unlike most electric bikes, the Skarper uses a combination of sensors and control algorithms to respond to the terrain and your input. Power delivery was smooth and predictable.
It’s akin to the level of assistance you get from lighter ebike systems, such as Mahle’s ebikemotion or Fazua’s mid-drive system. However, this self-contained unit, without a separate high-capacity battery, won’t have the same range as either of those systems.
The Skarper isn’t just for commuter bikes – you can fit it to your road bike, gravel bike, mountain bike or anything with a disc brake. Skarper
While the Skarper is pretty much self-contained and self-controlled, the brand is also working on a smartphone app to allow the owner to tune the system and perform firmware updates and upgrades.
I asked about long-term concerns on driving the rear wheel via the brake rotor. Darwood explains that the force a rotor experiences under braking far exceeds any amount of power the Skarper system delivers. This, he says, means the system is said to operate well within existing standards.
With removal in seconds, compact dimensions and a 2.5-hour recharge time, the Skarper can truly be charged at your desk. Skarper
Having spent 45 minutes riding the Skarper, and in prototype guise with a fabricated casing around the patented internals, I’m not ready to commit to a full-test opinion yet.
I was, however, impressed by just how good the system feels.
There’s enough power for urban hills and the power curve is smooth, progressive and instant in both turning on and off. The system also feels essentially drag-free when it’s not running (above the 25kph EU limit).

Skarper’s COO, Uri Meirovich, was quick to point out after my short test ride that the aim of the system is not to take on existing conversion kits, but to offer a viable alternative to expensive mid-drive and hub motor systems without the need to purchase a full-on electric bike.
The goal of producing a credible alternative to existing ebikes, while you can still use your own bike is potentially game-changing, but we’ll have to reserve judgement until we can get the Skarper on long-term test.
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Warren Rossiter
Warren Rossiter is BikeRadar and Cycling Plus magazine’s senior technical editor for road and gravel. Having been testing bikes for more than 20 years, Warren has an encyclopedic knowledge of road cycling and has been the mastermind behind our Road Bike of the Year test for more than a decade. He’s also a regular presenter on the BikeRadar Podcast and on BikeRadar’s YouTube channel. In his time as a cycling journalist, Warren has written for Mountain Biking UK, What Mountain Bike, Urban Cyclist, Procycling, Cyclingnews, Total Bike, Total Mountain Bike and T3. Over the years, Warren has written about thousands of bikes and tested more than 2,500 – from budget road bikes to five-figure superbikes. He has covered all the major innovations in cycling this century, and reported from launches, trade shows and industry events in Europe, Asia, Australia, North American and Africa. While Warren loves fast road bikes and the latest gravel bikes, he also believes electric bikes are the future of transport. You’ll regularly find him commuting on an ebike and he longs for the day when everyone else follows suit. You will find snaps of Warren’s daily rides on the Instagram account of our sister publication, Cycling Plus (@cyclingplus).